Tagged Questions

An asymmetric cipher is an encryption scheme using a pair of keys, one to encrypt and a second to decrypt a message. A special class of asymmetric ciphers are public-key ciphers, in which the encrypting key need not be kept secret to ensure a private communication.

I am looking for an asymmetric encryption algorithm, which allows to encrypt a secret with multiple public keys, but to reveal the secret all private keys must be used. You shouldn't be able to tell ...

The four Public-key cryptosystems: RSA, ElGamel, DH, and Rabin (all with others) all require some group operations in an integer field or multiplication group of some residue classes. When it comes ...

I know that there are cases when RSA will not work like when the number to feed into the system is greater than the modulus. I was wondering if there were any other cases when RSA won't work
I looked ...

The general scenario of hybrid encryption is to use public key cryptography for the exchange of a one time session key that can be used for the encryption of the plaintext with a symmetric encryption ...

I was reading this question about generating primes for RSA keys. The answers point out that most implementations of of the algorithm use probabilistic prime-ness checking algorithms. The answer by ...

I am facing a challenge at university.
Our teacher give us the challenge to try to break an RSA 1024 bit.
We have public modulus N and public exponent e (0x03), we don't know the padding.
We have a ...

I'm trying to get my server to establish trust with a client. Neither is on the Internet, so there are no certificate authorities. The typical way to establish trust in my domain is for a client to ...

Suppose we have three parties, Alice, Bob, and Carol. Alice can receive messages from Bob and Carol individually, but can only send messages to both simultaneously. Additionally, Alice cannot tell if ...

Is it possible (how) to recover public (512 bit long) RSA key from multiple signatures having corresponding plain texts. Padding is not randomized.
I need it to verify any future message comming from ...

I was reading the Wikipedia article on Post Quantum Cryptography and was interested in opinions as to whether the Supersingular Elliptic Curve Isogeny Diffie-Hellman listed there would be a good Post ...

I have noticed, during the period I spent studying RSA, that Euler's Totient function can be calculated in another way than $ϕ(N) =(p-1).(q-1)$
Let me explain myself by pointing to a brief example:
...

I'm on the study of Diffie-Hellman and its related math (multiplicative group of integers $\mod n$).
In some crypto papers and documents I've read that $g$ needs to be a primitive root mod $n$ ($g$ ...

We are creating a device with a small microcontroller (20 MHz CPU 16 KiB RAM).
We need some way to securely send signed files to device (only signature, no encryption necessary). An external company ...

Are there any practical limitations? Govt driving license, passport, SSN could be digitally signed making it easy for anyone to validate. They can have a qr code in them which can be easily validated ...

I would like to know if there is any security issue in sharing a secret key (of an asymmetric cryptography) between several users.
I know that this secret key is no longer "secret", so it's no longer ...

I have been trying to use Go (I could post the code, but I think I posted enough already...) to generate a PGP RSA key. However every time I try to encrypt something with it, something fails. However, ...

Is there something like a perfect asymmetric crypto-algo? Is there proof that there must be one or not. From a logical point of view it seems to be possible to design such algorithm if your keysize is ...

The specifications for RSA state: $P^{\phi(N)} \equiv 1 ~mod~N$ if and only if $P$ and $N$ are coprime. Here $P$ is the plaintext and $N$ is the product of two suitable primes $x_1, x_2$. My question ...

I'm looking for a standard, or sound industry practice, for the equivalent of a Key Check Value, applied to the private key of a public key algorithm, like ECDSA.
For DES or 3DES keys, practice (as ...

I am studying (sliding) window method in Elliptic Curve Cryptography (ECC) but I am confused by the term, signed fixed window method. By the way term is used in a research paper and not in the book ...